If your company uses a business edition of Office 365, here’s a nifty trick for sharing a file. Upload your file to Office 365’s cloud storage. Fire up the cloud version of Outlook (known as Outlook Web App) and, instead of attaching a file, link to the file on your cloud.
This isn’t unique to Office 365 — all cloud storage services allow you share documents via links. But Outlook will automatically grant edit permission to the people you are emailing. (You can change their permissions, too.)